Project description:Concerning the roles of LCN2 in chronic inflammation and fibrosis, we investigated chronic liver inflammation and fibrosis using repeated carbon tetrachloride (CCl4) in mineral oil injection. We found that mice treated with the mineral oil vehicle alone also showed liver inflammation and more severe in wild-type mice compared to lipocalin 2 null mice.
Project description:IL-36, which belongs to the IL-1 superfamily, is increasingly linked to neutrophilic inflammation. Here, we performed single-cell RNA-seq on an acute LPS mouse model of lung inflammation to provide insights into the intercellular signaling pathways and mechanisms through which IL-36 promotes lung inflammation. We identified neutrophils as a source of IL-36 which provides a rationale for targeting IL-36 to improve treatment of a variety of neutrophilic lung diseases.
Project description:IGF1R (Insulin-like Growth Factor 1 Receptor) is a ubiquitously expressed transmembrane tyrosine kinase receptor with multiple functions including inflammation. IGF activity maintains human lung homeostasis, being involved in relevant pulmonary diseases with an inflammatory component, such as lung cancer, COPD, asthma and pulmonary fibrosis. Here we examined the role of IGF1R in lung inflammation using mice with a postnatal deficiency of Igf1r and a model of bleomycin(BLM)-induced lung injury. Lung transcriptome analysis of Igf1r-deficient mice showed a general inhibition of transcription of genes related to epigenetics, inflammation/immune response and oxidative stress activity with potential pulmonary protective roles. Early upon intratracheal BLM treatment, mutant mice showed improved survival and milder pulmonary injury and inflammation. Their lungs presented down-regulation of macrophage (Marco/Adgre1), neutrophil-related (Cxcl1/Ly6g), pro-inflammatory (Tnf/Il1b/Il6), endothelial adhesion (Icam1/Pecam1) and alveolar damage (Aqp5/Sftpc) markers and up-regulation of resolution phase markers (Csf1/Il13/Cd209a). Changes in mRNA of IGF system genes were also found, in parallel to a hindered response to hypoxia (Hif1a) and increased expression of the anti-oxidative stress marker Gpx8. These findings identify Igf1r as an important player in oxidative stress and inflammation and suggest that targeting Igf1r may block the inflammatory response in lung diseases with this component.
Project description:Members of the lipocalin protein family serve as biomarkers for kidney disease and acute phase inflammatory reactions, and are under pre-clinical development for the diagnosis and therapy of allergies. However, none of the lipocalin family members has made the step into clinical development, mostly due to their complex biological activity and the lack of in-depth mechanistic knowledge. Here, we show that the hepatokine lipocalin 13 (LCN13) triggers glucose-dependent insulin secretion and cell proliferation of primary mouse islets. However, inhibition of endogenous LCN13 expression in lean mice did not alter glucose and lipid homeostasis. Enhanced hepatic secretion of LCN13 in either diet-induced or genetic obesity led to no discernable impact on systemic energy homeostasis, neither in preventive nor therapeutic setting. Of note, loss or forced LCN13 hepatic secretion did not trigger any compensatory regulation of related lipocalin family members. Together, these data are in stark contrast to the suggested gluco-regulatory and therapeutic role of LCN13 in obesity, and imply complex regulatory steps in LCN13 biology at the organismic level mitigating its principal insulinotropic effects.
Project description:Macrophages play critical roles in inflammation and tissue homeostasis, and their functions are regulated by various autocrine, paracrine, and endocrine factors. We have previously shown that CTRP6, a secreted protein of the C1q family, targets both adipocytes and macrophages to promote obesity-linked inflammation in adipose tissue. However, the gene programs and signaling pathways directly regulated by CTRP6 in macrophage remain unknown. Here, we combine transcriptomic and phosphoproteomic analyses to show that CTRP6 activates inflammatory gene programs and signaling pathways in bone marrow-derived macrophages (BMDMs). Treatment of BMDMs with CTRP6 upregulates proinflammatory, and suppresses the anti-inflammatory, gene expression. We show that CTRP6 activates p44/42-MAPK, p38-MAPK, and NF-κB signalings to promote inflammatory cytokine secretion from BMDMs, and that pharmacologic inhibition of these signaling pathways largely abolish the effects of CTRP6. Pretreatment of BMDMs with CTRP6 further augments LPS-induced inflammatory signaling and cytokine secretion from BMDMs. Consistent with the metabolic phenotype of proinflammatory M1-like macrophages, CTRP6 treatment induces a shift toward aerobic glycolysis and lactate production, reduces oxidative metabolism, and elevates mitochondrial ROS production in BMDMs. We use a Ctrp6 knockout mouse model to further confirm the physiologic relevance of our in vitro findings. BMDMs from CTRP6-deficient mice are less inflammatory at baseline and show a marked suppression of LPS-induced inflammatory gene expression and cytokine secretion. Loss of CTRP6 in mice also dampens LPS-induced inflammation and hypothermia. Collectively, we provide mechanistic evidence that CTRP6 regulates macrophage function, and neutralizing CTRP6 activity may have beneficial effects in reducing inflammation.
Project description:melanocortin 5 receptor (Mc5r) have various effects in immune responses. However, the involvement of Mc5r in ILC2 functions remains unclear. We identified the genes regulated by Mc5r in lung ILC2s during papain induced acute lung inflammation.
